The effect of substrate RF losses on the characteristics of silicon-based integrated transformers is studied experimentally by using a substrate transfer technique. The maximum available gain is used to evaluate the quality of transformers similarly to that of active devices. The silicon substrate has a pronounced effect on the quality factor and mutual resistive coupling factor of the primary and secondary coils, thereby degrading the maximum available gain of the transformer. A highly structured patterned ground shield is shown to improve the maximum available gain of a transformer at high frequencies, while at low frequencies, it has little effect on the maximum available gain and even degrades the quality factors of the transformer coils. It is shown that the low-frequency degradation of the coil quality factors relates to local eddy currents in the patterned metal shield.

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Substrate effects in monolithic RF transformers on silicon

This paper presents a new method and circuit for the conversion of binary phase-shift keying (BPSK) signals into amplitude shift keying signals. The basic principles of the conversion method are the superharmonic injection and locking of oscillator circuits, and interference phenomena. The first one is used to synchronize the oscillators, while the second is used to generate an amplitude interference pattern that reproduces the original phase modulation. When combined with an envelope detector, the proposed converter circuit allows the coherent demodulation of BPSK signals without need of any explicit carrier recovery system. The time response of the converter circuit to phase changes of the input signal, as well as the conversion limits, are discussed in detail.

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BPSK to ASK Signal Conversion Using Injection-Locked Oscillators&#8212;Part I: Theory

Adaptive CMOS analog circuits for 4G mobile terminals-Review and state-of-the-art survey

A system for the coherent demodulation of Binary Phase Shift keying (BPSK) signal at a frequency f, includes recovering a carrier signal (C) at a frequency 2f from the BPSK signal; injecting the signal having a frequency 2f in an injection locking oscillator (ILO), which has a natural resonant frequency f r which is substantially equal to f, to provide differential output (O p , O n ) signals which recover the original carrier with a phase shift of (θ e −k)/2, where θ e =arcsin ((f r −f)/(αA i f)) where α and k are parameters that depend on the type of predominant non-linearity in the injection locking oscillator (ILO), and A i is the amplitude of the recovered carrier signal at a frequency of 2f, and combining the differential output (O p , O n ) signals with a copy of the incoming BPSK signal to generate a demodulated signal (DEMOD).

System for coherent demodulation of binary phase shift keying signals (BPSK)

A receiver is described The receiver includes a first injection-locked oscillator having a first input configured to receive a BPSK signal and a second input configured to receive a first frequency reference The receiver also includes a second injection-locked oscillator having a third input configured to receive the BPSK signal and a fourth input configured to receive a second frequency reference Further, the receiver includes a first phase-locked loop coupled with the second input of the first injection-locked oscillator The first phase-locked loop is configured to generate the first frequency reference And, a second phase-locked loop is coupled with the fourth input of the second injection-locked oscillator The second phase-locked loop is configured to generate the second frequency reference

Receiver architecture and methods for demodulating binary phase shift keying signals

This work presents an alternative to generate continuous phase shift of sinusoidal signals based on the use of super harmonic injection locked oscillators (ILO). The proposed circuit is a second harmonic ILO with varactor diodes as tuning elements. In the locking state, by changing the varactor bias, a phase shift instead of a frequency shift is observed at the oscillator output. By combining two of these circuits, relative phases up to /spl plusmn/90/spl deg/ could be achieved. Two prototypes of the circuit have been implemented and tested, a hybrid version working in the range of 200-300 MHz and a multichip module (MCM) version covering the 900-1000 MHz band.

/pdf/continuous-phase-shift-of-sinusoidal-signals-using-injection-4d9gs1c28z.pdf

Continuous phase shift of sinusoidal signals using injection locked oscillators

This work presents a new circuit for the conversion of Binary Phase Shift Keying signals (BPSK) into Amplitude Shift Keying signals (ASK). The basic principles of the conversion method are the super harmonic injection of oscillator circuits and interference phenomena. The first one is used to synchronize the oscillators while the second is used to generate an amplitude interference pattern that reproduces the original phase modulation. When combined with an envelope detector, the proposed circuit allows the coherent demodulation of BPSK signals without the need of a carrier recovery system. Two prototypes of the converter have been implemented. The first one is a hybrid version working in the 300-400 MHz frequency range. The second has been implemented using Multi Chip Module (MCM) technology, and is intended for working in the range of 1.8-2.0 GHz. The time response of the converter to phase changes of the input signal is about 100 ns for the hybrid version and scales down to about 15 ns for the MCM version, giving upper limits for the modulation rate of about 5 Mbit/s and 30 Mbit/s, respectively.

BPSK to ASK converter for RF digital communications

In this work, different topologies of integrated planar transformers implemented in a MCM-D standard technology are analyzed using an EM simulator. Simulations are validated with measurements over a sample set of transformers. Moreover, losses in the strips are analyzed and differences between losses in inductors and transformers are pointed

Analysis of RF Monolithic Transformers

This work presents a new approach to the modelling of planar inductors for microwave and RF applications. The inductance is evaluated by means of analytical expressions based on a full geometry description. Moreover, the model takes into account the ohmic losses, due to conduction current, and the magnetic induced losses, due to Eddy currents by means of a frequency dependent series resistor. Finally, a parallel capacitance is included to match the frequency of the component at its first resonance.

Accurate Physical Model For Designing RF and Microwave Integrated Planar Inductors

On-chip passives, such as inductors, transformers, are key components in the design of RF building blocks when using VLSI technologies. Most of the time of the design cycle is used in the simulation of passives, trying to obtain the maximum performance. Recently, work on modelling of passives has been directed to pursuit fast computation algorithms due to the need to handle several passives in a complete RF circuit. However, small attention has been paid in the optimization of passives. The work presented tries to fill this gap. The algorithm is based on three steps: the split of the magnetic and electric modelling problem based in a PEEC description; a model order reduction, based on plausible arguments; and the use of analytical formulae to keep scalability. Fast computation is achieved thanks to both the separation of the magnetic and electric problem, and the model order reduction. By keeping an analytical formulation, the optimization of the layout for minimum losses is driven by a physical algorithm, instead of a mathematical one. The tool has been checked with experimental data from inductors fabricated in different VLSI technologies, showing its possibilities in the design of RF building blocks.

J. Cabanillas

Papers

Continuous phase shift of sinusoidal signals using injection locked oscillators

BPSK to ASK converter for RF digital communications

Analysis of RF Monolithic Transformers

Accurate Physical Model For Designing RF and Microwave Integrated Planar Inductors

Modeling of passive components in VLSI technologies